This invention relates generally to a pyramid beam splitter which permits the multiple split and precise right angle deflection of a laser beam. It also allows for a single beam right angle deflection. Any split or deflection direction is selectable.
Accurate, dependable measurement of bearings and directions are required for geologic mapping in subterranean shafts, such as, for example, nuclear waste storage investigations. A method of decreasing survey time (and therefore costs) while retaining accuracy and quality was needed. The time required to survey target locations is a major factor in the cost of geologic mapping for nuclear waste storage investigations. Also the quality assurance of the data is a major consideration. Previous methods consisted of conventional surveying (manually determining distances and angles) or, if using a laser distance-measuring device, manually measuring the angles.
Subterranean sites presently being investigated are in rock with natural magnetism and also contain steel structures. Previously, mapping of shafts could be done with extensive survey support to give geologists reference angles from which to measure the angles of the geologic features. Under these conditions, a surveyed reference (strike rail), is necessary with all directions or bearings related to the reference. Utilizing a conventional strike rail is time consuming and therefore extremely expensive. Previous methods consisted of obtaining bearings or directions from surveyed rails that had to be prepositioned around the periphery of the work platform. Magnetic compasses have been used but are not dependable.
Prior art devices such as disclosed in U.S. Pat. No. 2,579,067 to Cunningham, disclose some form of beam splitters/deflectors and U.S. Pat. No. 4,523,809 discloses a laser beam and a four facet pyramid prism. Other prior art devices such as disclosed in U.S. Pat. No. 4,150,897 to Roberts, disclose a laser which provides a laser beam to a rotating pyramid mounted forwardly and arranged to be continuously rotated. Mounted between the rotating pyramid and the lens is a movable pyramid. Neither these nor other prior art devices found disclose precise mechanical adjustment of the beam splitter as disclosed by the instant invention which overcomes the deficiencies of the prior art by the use of a pyramid beam splitter/deflector which is laterally translatable and radially adjustable.